Device for signaling the height of a pile of iron ore and the like



Nov. 15, 1966 A. CAPRA DEVICE FOR SIGNALING THE HEIGHT OF A PILE OF IRONORE AND THE LIKE Filed June 11, 1965 INVENTOR. LAWRENCE A. CAPRA I Wa WATTQRNEYS United States Patent Office 3,286,053 Patented Nov. 15, 19663,286,053 DEVICE FOR SIGNALHNG THE HEIGHT OF A PILE OF IRON ORE AND THELIKE Lawrence A. Capra, Iron Mountain, Mich., assignor to M. J.Electric, Inc., Iron Mountain, Mich, a corporation of Michigan FiledJune 11, 1965, Ser. No. 463,162 14 Claims. (Cl. 200-6121) This inventionrelates generally to devices for indicating the level of stock piledmaterial, and more particularly, to an electromechanical level indicatorfor detecting the relative height of stock piled material and forsending an electrical signal to indicate various conditions of the pile.

The problem of detecting the height of stock piled material may besolved easily when the material is magnetic. However, a further problemexists when the material being stock-piled is non-magnetic,non-conductive, and virtually non-detectable by conventional electronicmeans. Heretofore, attempts have been made to overcome the problemsinvolved in determining the level of stock piles of the last mentionedmaterials. Examples of such attempts are shown in the various indicatorsdescribed in US. Patents Nos. 2,961,842, 3,019,310, and 3,114,804.However, the prior art devices shown in the enclosed patents do notsolve the problem of indicating the height of stock piles of materialstock-piled in the open. Furthermore, the prior art devices are subjectto being damaged or destroyed by the material being stockpiled, as forexample, six inch limestone rock.

In view of the foregoing, it is an important object of the presentinvention to provide a novel and improved stock pile level indicatorwhich can detect the relative height of material being stock-piled andwhich can send an electrical signal to indicate various conditions ofthe stock pile. The signal may be used to activate visual or audioalarms, or to cause the stacking machine to be moved to a new location.

It is another object of the present invention to provide a novel stockpile level indicator which is adapted to indicate the height of a stockpiled material regardless of whether the material isnon-magnetic,'n-on-conductive or non-detectable by conventionalelectronic means.

t is a further object of the present invention to provide a novel andimproved electromechanical level indicator to indicate the relativeheight of stock piled material.

It is still another object of the present invention to provide a novelstock pile material level indicator which is constructed to preventitself from being physically damaged or destroyed by the material beingstock-piled, such as limestone rock material.

It is still another object of the present invention to provide a novelstock pile level indicator which is adapted to be mounted on a movablestacking machine, and which includes a motor that drives a stock pilelevel sensing arm upwardly and downwardly, said motor being pivotallymounted, whereby when the level of the stock pile reaches a certainheight the sensing arm will be retarded in its upward and downwardmovement, and such retarding action will be offset .by the motorpivoting about its support, and switch means actuated by the motor whenit is pivoted about its support to send an electric signal to an alarmor to cause the stacking machine to move to a new location.

Other objects, features and advantages of this invention will beapparent from the following detailed description, appended claims, andthe accompanying drawing.

In the drawing:

FIG. 1 is an elevational view of a level indicator made in accordancewith the principles of the present invention,

and showing the level indicator in operative position over a stock pileof stacked material;

FIG. 2 is a fragmentary plan view of part of the structure illustratedin FIG. 1, taken along the line 2-2 thereof, and looking in thedirection of the arrows;

FIG. 3 is a schematic view of an illustrative electrical control circuitfor the structure of FIG. 1; and,

FIG. 4 is a schematic view of a dash pot apparatus adapted to be used inthe structure of FIG. 1.

Referring now to the drawing and in particular to FIG. 1, the numeral 10generally indicates a stock pile of material being piled in an openfield by a conventional stacking machine. The numeral 11 generallydesignates a vertically disposed mounting plate which would be carriedon the stacking machine in a suitable position for carrying a stock pilelevel indicator apparatus as described hereinafter. The numeral :12generally designates a suitable electric mot-or which is fixed on themounting :bracket 13. The bracket 13 is fixed on a platform or baseplate 14. As shown in FIG. 1, the platform 14 is horizontally disposedand is provided on the lower side thereof, on the right end thereof, asviewed in FIG. 1, with a base plate mounting journal 15.

As shown in FIG. 1, a horizontally disposed stub shaft 16 is fixed onthe lower end of the mounting plate 11, adjacent the lower right cornerthereof. The platform mounting journal 15 is pivotally mounted on theshaft 16. A speed reduction means 17 is operatively connected to theelectric motor 12. Any suitable speed reduction means may be used, asfor example, a suitable gear reduction unit. The speed reduction means17 is fixed on the mounting bracket 18 which is secured to the left endof the platform 14, as viewed in FIG. 1. The platform 14 is supported atthe left end thereof, as viewed in FIG. 1, by the angle bracket 19 whichforms a stop means or support means for the left end of the platform 14.

The numeral 30 indicates the power output shaft of the speed reductionmeans 17. Fixed on the output shaft 20 is the rotary drive crank arm 21which rotates with the shaft 20 when the electric motor 12 is operating.The short crank arm 21 carries the shaft 22 on the outer end there-of.Pivotally mounted on the shaft 22 is the long crank arm 23. The lowerend of the crank arm 23 is connected pivotally by the pin 24 to theknuckle 26 formed at a substantially intermediate point on anoscillating arm 25. As shown in FIG. 1, the inner end of the oscillatingarm 25 is provided with the journal 27 which is mounted pivotally orhingedly on the outer end of the motor support shaft 16. The outer endof the oscillating arm 25 is provided with a rod holder 28 for holdingthe steel rod or tine 30. The steel rod 30' is mounted in the hole 29formed in the holder 28. The rod 30 is secured in an adjusted positionby means of the set screw 32. As shown in FIG. 1, the lower end of therod 30 is adapted to engage the sloping surface 32 of the stock piledmaterial 10 for indicating thelevel of the material 10.

As shown in FIGS. 1 and 4, the motor 12 and the speed reduction means 17are connected to a dash pot means, generally indicated by the numeral33. Fixed to the upper side of the speed reduction means 17 is a bracket39 which is connected by the pin 38 to the piston rod 37. The rod 37 isfixed to a piston 36 which is operatively mounted in the cylinder of thedash pot 33, as shown in FIG. 4. The cylinder of the dash pot 33 isconnected by the hinge pin 34 to the bracket 35 (FIG. 1) which is inturn supported on the upper end of the mounting plate 11. As shown inFIG. 4, the cylinder of the dash pot 33 is provided with an opening 40in the upper end thereof which communicates the upper closed end of thecylinder to the atmosphere and permits free entry and exit ofatmospheric air. The lower end of the dash pot cy-linder is alsoenclosed and the piston rod 37 is slidably mounted through the lowerclosed end of the dash pot cylinder in a suitable manner.

The opening-40 in the dash pot cylinder permits the piston 36 to movefreely upward and the movement of the piston 36 downwardly is controlledor regulated by the check valve means, generally indicated by thenumeral 41. It will be understood that the check valve means 41 ismerely illustrative of one suitable means which may accomplish thefunction of controlling the air flow into and out of the lower end ofthe dash pot cylinder.

The check valve means 41 is connected by the conduit 43 which has oneend thereof, indicated by the numeral 42, communicating with the lowerend of the dash pot cylinder. The other end of conduit 43 communicateswith the passage 44 of the check valve means 41. The entrance end of thepassage 44 is normally closed by the spring biased check valve 46 whichis made in the form of a ball. The amount of air flowing through thepassage 44 is controlled 'by' the threadably mounted, adjustable needlevalve 45. It will 'be seen that air can be conducted from the lower endof the dash pot cylinder through the conduit 43 and the passage 44. Theair forced out of the dash pot cylinder by the downwardly moving piston'36 will unseat the ball check valve 46 and permit the exhausting air topass out through the passage 47 to the atmosphere. Air may be drawn intothe lower end of the dash pot cylinder through the passage 47 and theinlet passage 48 which communicates with the conduit 43.

The amount of intake air flowing into the inlet passage 48 is controlledby the setting of the needle valve 49.

When the dash pot piston 36 is moved upwardly, air will flow into thelower end of the dash pot cylinder by the unseating of the spring biasedball check valve or ball 50. The needle valves 45 and 49 will .beadjusted to admit the proper volume of air to flow into and out of thedash pot cylinder during movements of the piston 36 upwardly anddownwardly so as to cushion the downward movement of the motor 12 andspeed reduction means 17, yet permit free upward movement of the piston.

As shown in FIG. 1, a cam 51 is adjustably mounted on the upper side ofthe motor 12 and it is adapted to engage the limit switches 52 and 53when the motor 12 and the speed reduction means 17 is pivoted in aclockwise direction, as viewed in FIG. 1, as explained hereinafter. Thenumerals 54 and 55 indicate the various operative positions of the cam51 when it operates the limit switches 52 and 53, respectively.

It will 'be understood that the stock pile level indicator shown in FIG.1 may 'be used to perform various control functions. An illustrativecontrol circuit is schematically illustrated in FIG. 3. The numerals 56and 57 indicate a pair of power lead wires connected to a suitablesource of electrical power. The numeral 58 indicates the electric motorwhich would operate the stacking machine. The numeral 59 indicates amanual start switch which would be closed to energize the controlcircuit when the stacking machine is started. As shown in FIG. 3, thestacking machine operating motor 58 is connected between the power lines56 and 57 by the manually oper- :ated switch 59, and the cam operatedlimit switch 53. A suitable visual indicator or alarm 60 in the form ofa lamp is connected between the power lines 56 and 57 by the limitswitch 52. The limit switch 52 is a normally open switch, and the limitswitch 53 is a normally closed switch. An audio alarm such as anelectrically operated bell may also be energized by the closing of thelimit switch 52, as shown in FIG. 3. The numeral 62 indicates a motorfor the drive mechanism which would propel the stacking machine to a newlocation when the limit switch 52 is closed.

In use, when the stock pile level indicator apparatus of the presentinvention is mounted on a stacking machine, the motor 1.2 would 'beenergized to operate the speed reduction means 17 which would rotate thearm 21 and in turn move the crank arm 23 upwardly and downwardly tooscillate the arm 25 upwardly and downwardly. Assuming that the surface32 of the stock pile 10 is 'below the lowest point to which the arm 25travels downwardly, the arm 25 will oscillate upwardly and downwardly ina free motion. As the surface 32 ofthe stock pile 10 rises the arm 25will be restricted in its oscillating movement. The platform 14 ismounted so that it will pivot about the shaft 16, and accordingly, whenthe lower end of the rod 30 commences to strike the surface 32 of thestock pile 10, as the surface 32 rises, a reactive force will betransmit-ted from the rod 30 and pass to the arm 25 and through thecrank arms 23 and 21 to the motor 12 and speed reduction means 17 tocause the platform 14, motor 12 and speed reduction means 17 to pivotabout the shaft 16 in a clockwise direction, as viewed in FIG. 1. Therod 30 is strong and rigid to support the weight of the motor 12 andspeed reduction means 17 during the pivoting of the same. As the level32 of the stock pile 10 rises, the motor 12 will be pivoted an everincreasing amount, whereby the cam 51 will eventually move to the dottedposition marked by the numeral 54 so as to actuate the limit switch 52.As shown in FIG. 3, when the limit switch 52 is actuated, a suitableaudio alarm 61 and a suitable visual alarm 60 may be energized and thestacking machine propelling motor 62 energized to move the stackingmachine to a new location. -The moving of the stacking machine willpermit the arm 25 to again oscillate freely throughout its whole lengthof travel without having the lower end of the rod 30 engage the surface32 of the pile 30. The surface 32 of a stock pile at the new position towhich the stacking machine has been propelled will 'be lower than themaximum downward movement of the arm 25, and the lower end of the rod30, and the motor 12 and speed reduction means 17 will not be rotated.The platform 14 remains in a seating position on the stop member 19.

It will be understood that the normally open limit switch 52 is used fora normal signal and for energizing the propelling motor 62 to move thestacking machine to a new location. The normally closed limit switch 53is actuated when the motor 12 is pivoted to a position so as to bringthe cam 51 to the dotted line position indicated in FIG. 1 by thenumeral 55. The limit switch 53 is then open and may be used for a highalarm or shutdown condition. It will be seen that the cam 51 must berotated further to actuate the limit switch 53 as compared to theposition for actuating the limit switch 52. The cam 51 may be set forany desired high stack condi tion for the stock pile.

It will be understood that the dash pot 33 provides relatively freemovement of the piston in the upward direction, but the movement of thepiston 36 may be restricted inthe downward direction by the check valvemeans 41 which restricts the escapement of air out of the lower end ofthe cylinder of the dash pot 33. This restricted downward movement ofthe piston 36 and the motor 12 and speed reduction means 17 permits theplatform 14 to be seated on the stop 19 without an abrupt stoppingcondition.

Experience has shown that the stock pile level indicator of the presentinvention is an eflicient and practical means for determining the levelof a stock pile of material disposed in an open lot, and it willfunction on a stock pile of material which is non-magnetic,non-conductive and non-detectable by conventional electronic means.

While it will be apparent that the preferred embodiment of the inventionherein disclosed is well calculated to fulfill the objects above stated,it will be appreciated that the invention is susceptible tomodification, variation and change without departing from the properscope or fair meaning of the subjoined claims.

What I claim is:

1. In an apparatus for indicating the level of a stock pile, thecombination comprising:

(a) a support member;

(b) a horizontal shaft on said support member;

(c) an arm having one end pivotally mounted on said horizontal shaft andthe other end freely movable upwardly and downwardly in an arcuate pathabout said shaft;

(d) a horizontal platform having one end pivotally mounted on saidhorizontal shaft and the other end normally disposed on a stop memberand being movable upwardly from said stop member in a swinging movementabout said horizontal shaft;

(e) means on said platform for moving said arm upwardly and downwardlyin an oscillatory motion; (f) means carried by said arm engageable withthe level of a stock pile when the level of a stock pile reaches apredetermined height, whereby said arm is retarded in the downwardmovement and a reactive force is exerted on said platform to pivot thesame about said shaft and create a signal; and,

(g) a dash pot means operatively connected to said platform and meansfor moving said arm to restrict the downward movement of the platformand provide free upward movement for the platform.

2. The apparatus for indicating the level of a stock .pile as defined inclaim 1, wherein:

(a) said dash pot means includes an air cylinder and means forcontrolling the air flow into and out of said air cylinder.

3. The apparatus for indicating the level of a stock pile as defined inclaim 1, wherein:

(a) said means for moving said arm upwardly and downwardly includes amotor on said platform adjacent said horizontal shaft, and a speedreduction means on the other end of said platform and operativelyconnected to said motor.

4. The apparatus for indicating the level of a stock pile as defined inclaim 3, including:

(a) an output shaft on said speed reduction means;

(b) a first crank having one end fixed to said output shaft and theother end provided with a pivot pin; and,

(c) a second crank having the upper end pivotally mounted on said pivotpin and the lower end pivotally connected to said arm.

5. The apparatus for indicating the level of a stock pile as defined inclaim 4, wherein:

(a) said means carried by said arm includes a rod engagable with thesurface of a stock pile when the stock pile reaches a predeterminedheight, whereby said arm will be restricted in the downward movement anda reactive force will be exerted through said first and second cranksand through said speed reduction means to said platform so as to pivotthe platform about said shaft and create a signal.

6. The apparatus for indicating the level of a stock pile as defined inclaim 5, wherein:

(a) said dash pot means is connected to said speed reduction means.

7. The apparatus for indicating the level of a stock pile as defined inclaim 1, wherein:

(a) a cam is operatively mounted on said means for moving said arm; and,

(b) the apparatus for indicating the level of a stock pile includes acontrol system actuated by said cam.

8. The apparatus for indicating the level of a stock pile as defined inclaim 7, wherein:

(a) said control system includes at least two limit switches operatedsuccessively by said cam when said platform is pivoted about said shaft.

9. The apparatus for indicating the level of a stock pile as defined inclaim 8, wherein:

(a) said control system further includes an alarm means energized bysaid limit switches; and,

(b) said control system also includes means for shutting down theapparatus when said platform is pivoted about said shaft a predetermineddistance.

10. The apparatus for indicating the level of a stock pile as defined inclaim 9, wherein:

(a) said dash pot means is connected to said speed reduction means; and,

(b) means for controlling the air flow into and out of said cylinder torestrict the downward movement of the platform and provide free upwardmovement for the platform.

11. The apparatus for indicating the level of a stock pile as defined inclaim 10, wherein:

(a) said cam is adjustably mounted on said motor.

12. In an apparatus for indicating the level of a stock pile, thecombination comprising:

(a) a support member;

(b) an arm having one end pivotally mounted on said support member;

(0) means for moving said arm upwardly and downwardly in an oscillatorymotion;

(d) a platform having one end pivotally mounted on said support memberand the other end normally disposed on a stop member and being movableupwardly from said stop member in a swinging movement about the pivot onsaid one end;

(e) said means for moving said arm being mounted on said platform;

(f) means carried by said arm engagable with the level of a stock pilewhen the level of a stock pile reaches a predetermined height, wherebysaid arm is retarded in the downward movement and a reactive force isexerted on said platform to pivot the same and create a signal; and,

(g) a dash pot means operatively connected to said platform and meansfor moving said arm to restrict the downward movement of the platformand provide free upward movement for the platform.

13. The apparatus for indicating the level of a stock pile as defined inclaim 12, wherein:

(a) said dash pot means includes an air cylinder and means forcontrolling the air flow into and out of said air cylinder.

14. The apparatus for indicating the level of a stock pile as defined inclaim 13, wherein:

(a) said dash pot means includes a piston slidably mounted in said aircylinder, a piston rod connected at one end to said piston and at theother end to said means for moving said arm upwardly and downwardly.

References Cited by the Examiner UNITED STATES PATENTS 2,836,038 5/1958Morgan 62l37 3,210,495 10/1965 Lau 200-61.2l

BERNARD A. GILHEANY, Primary Examiner. R. N. ENVALL, JR., AssistantExaminer.

12. IN AN APPARATUS FOR INDICATING THE LEVEL OF A STOCK PILE, THECOMBINATION COMPRISING: (A) A SUPPORT MEMBER; (B) AN ARM HAVING ONE ENDPIVOTALLY MOUNTED ON SAID SUPORT MEMBER; (C) MEANS FOR MOVING SAID ARMUPWARDLY AND DOWNWARDLY IN AN OSCILLATORY MOTION; (D) A PLATFORM HAVINGONE END PIVOTALLY MOUNTED ON SAID SUPPORT MEMBER AND THE OTHER ENDNORMALLY DISPOSED ON A STOP MEMBER AND BEING MOVABLE UPWARDLY FROM SAIDSTOP MEMBER IN A SWINGING MOVEMENT ABOUT THE PIVOT ON SAID ONE END; (E)SAID MEANS FOR MOVING SAID ARM BEING MOUNTED ON SAID PLATFORM; (F) MEANSCARRIED BY SAID ARM ENGAGABLE WITH THE LEVEL OF A STOCK PILE WHEN THELEVEL OF A STOCK PILE REACHES A PREDETERMINED HEIGHT, WHERBY SAID ARM ISRETARDED IN THE DOWNWARD MOVEMENT AND A REACTIVE FORCE IS EXERTED ONSAID PLATFORM TO PIVOT THE SAME AND CREATE A SIGNAL; AND, (G) A DASH POTMEANS OPERATIVELY CONNECTED TO SAID PLATFORM AND MEANS FOR MOVING SAIDARM TO RESTRICT THE DOWNWARD MOVEMENT OF THE PLATFORM AND PROVIDE FREEUPWARD MOVEMENT FOR THE PLATFORM.